What is runaway diesel syndrom?

[Dieselguy123]

Hey all, I have been reading the posts and I noticed a couple times someone mention the runaway diesel . What is this and how is it caused? I have worked on gassers for a while but I am fairly new to diesels......so I am just curious> thanks Brad T.C. Michigan

 

[Freight_Train]

Run away is just that.The engine revs uncontrollably and cannot be shut off.It is caused by an uncontrolled feed of fuel into the Cylinders.This can be anything from a failed Injection pump to a bad CDR valve allowing engine oil into the intake.The most common is a failed turbo.We had a semi a few years ago that had it's turbo explode and the engine was still pumping oil which now that the center section was damaged was allowing the oil to spray into the intake.To shut down any of these problems you either have to stall the engine(which could be difficult since there is a possibility the engine is making some major Horse power and RPM,or shut off the air intake by blocking the intake manifold,or heaven forbid either let it keep going till a rod lets go or it sucks all the oil from the pan and at that point locks up or shuts down from fuel starvation.Unless you shut down within a couple seconds your pretty much screwed since she will be turning some Major RPM.

 

[ttman4]

Run away is just that.The engine revs uncontrollably and cannot be shut off.It is caused by an uncontrolled feed of fuel into the Cylinders.

Diesels keep running & revving as long as fuel and air are available to be injected or sucked into the cylinder. The governor's only purpose is to shut off the fuel supply at the set higher RPMs.
As it has been said other places, these diesels are "Oil Squeezers" & will run on any oil based fuel (or other flammables) as long as it is supplied & compressed.

Several years ago gas pipe was being unloaded & strung along a big natural gas pipeline, another piece of equiptment hit & ruptured a line & nat. gas went everywhere. Several pieces of equiptment & an ideling semi truck with diesel engines revved bigtime & a couple blew engines. When the semi's engine threw rods & busted the block, it all exploded (the job site) & a lot of stuff burned....couple guys got burned a little.
I guess it was just like squirting a really big can of ether into the air intakes & not letting go.
And it was unreal how really, really fast all this happened...from start to finish, just seconds.
ssssSSSSzzzZZZZZZZZKEEERRR-BOOM!!

 

[Agnem]

That would be a real mind blower if there was no one around at the time to smell the gas. Guys would just hear all this equipment racing out of control with no explaination for it.

 

[Mr_Roboto]

Diesels in coal mines are retrofitted with throttle plates so they can be rev limited by air restriction. The coal dust in the air will burn just like any liquid fuel.

 

[Diesel JD]

coal dust

This is a fact. I believe old Dr. Diesel experimented with coal dusta s diesel fuel.

 

[oldmisterbill]

We had a 5 ton,multifuel when I was in germany that ran away on motor oil.(turbo seals)It was the second deisel I saw run away.the first was scary and was stalled by stuffing a field jacket into the intake.The second 1 was saved by shooting a co2 fire extingusher into the intake.Once they get going you can't shift them into gear so you cant stall them mechanically.
My 2 bits

 

[Agnem]

GE experimented with diesels running on coal slurry, but that was through the fuel system and not the air. It's almost enough to make you wonder if we all shouldn't have some kind of rig like they put on the pulling tractors to snap off the air flow, just in case.

 

[Freight_Train]

hee hee hee.That is one of the things on my never to get to list.......Use a 3" Exhaust cut out valve(one of those cool electric ones) or borrow a 3-4" waffer valve from work(talk about over kill!Cast iron!)

 

[Exekiel69]

Once they get going you can't shift them into gear so you cant stall them mechanically.
My 2 bits

Thank You Mr Bill I was wondering if that was possible.

 

[Freight_Train]

Trust me OMB,There are ways.If your despirate enough you can jam that sucker into gear........I was told I couldn't Get my Lil Deuce Coupe outta gear when a buddy backed it up a mountian side and into a bunch of trees when he found out there was no clutch left.Not fun when you get the word that the truck backed up a near 45degree hill,Transmission in reverse,No clutch and engine is shut off.Well,I managed to stick both feet on the dash and slowly and carefully pull back on the shifter till it came out.

 

[Agnem]

Now we know why so much of your stuff is broken.

 

[rancherman84]

i had the unforunate experience with this a few weeks ago,it was on a mercedes engine in a CLAAS JAGUAR.guy was chopping and the turbo went bad,caused black smoke and no power.he shut it off and called parts for a turbo.installed the turbo himself and started the engine,it idled fine,smoked a little but ran fine,but when he went to wide open(the choppers only have idle and wide open)the engine went to about 6,000 rpm or higher ran for about 45 seconds and blew all the head gaskits then siezed up.
what he didnt do was clean the oil from the intercooler that the bad turbo pumped full.when he went to WOT the engine sucked the oil into it and ran away.
got it tore apart and found it has melted two out of six pistons to the liners.

 

[hugeredford]

Rancherman I saw claas has a 1000hp chopper do you know what the engine is? Thats all the hp on our farm-combined

 

[adrianspeeder]

Out of control chain reaction